Single-atom modified graphene cocatalyst for enhanced photocatalytic CO_(2) reduction on halide perovskite  

钴单原子修饰的石墨烯助催化剂用于提高卤化物钙钛矿光催化CO_(2)还原活性

作　　者：Hui Fu Jin Tian Qianqian Zhang Zhaoke Zheng Hefeng Cheng Yuanyuan Liu Baibiao Huang Peng Wang 付辉;田金;张倩倩;郑昭科;程合峰;刘媛媛;黄柏标;王朋(山东大学晶体材料国家重点实验室,山东济南250100)

机构地区：[1]State Key Laboratory of Crystal Materials,Shandong University,Jinan 250100,Shandong,China

出　　处：《Chinese Journal of Catalysis》2024年第9期143-151,共9页催化学报（英文）

基　　金：国家自然科学基金(22072071);山东省自然科学基金(ZR2022ZD25);国家重点研发计划(2020YFA0710301).

摘　　要：Metal halide perovskite(MHP)has become one of the most promising materials for photocatalytic CO_(2) reduction owing to the wide light absorption range,negative conduction band position and high reduction ability.However,photoreduction of CO_(2) by MHP remains a challenge because of the slow charge separation and transfer.Herein,a cobalt single-atom modified nitrogen-doped graphene(Co-NG)cocatalyst is prepared for enhanced photocatalytic CO_(2) reduction of bismuth-based MHP Cs_(3)Bi_(2)Br_(9).The optimal Cs_(3)Bi_(2)Br_(9)/Co-NG composite exhibits the CO production rate of 123.16μmol g^(-1)h^(-1),which is 17.3 times higher than that of Cs_(3)Bi_(2)Br_(9).Moreover,the Cs_(3)Bi_(2)Br_(9)/Co-NG composite photocatalyst exhibits nearly 100% CO selectivity as well as impressive long-term stability.Charge carrier dynamic characterizations such as Kelvin probe force microscopy(KPFM),single-particle PL microscope and transient absorption(TA)spectroscopy demonstrate the vital role of Co-NG cocatalyst in accelerating the transfer and separation of photogenerated charges and improving photocatalytic performance.The reaction mechanism has been demonstrated by in situ diffuse reflectance infrared Fourier-transform spectroscopy measurement.In addition,in situ X-ray photoelectron spectroscopy test and theoretical calculation reveal the reaction reactive sites and reaction energy barriers,demonstrating that the introduction of Co-NG promotes the formation of ^(*)COOH intermediate,providing sufficient evidence for the highly selective generation of CO.This work provides an effective single-atom-based cocatalyst modification strategy for photocatalytic CO_(2) reduction and is expected to shed light on other photocatalytic applications.温室气体CO_(2)的过量排放不仅对生存环境造成了威胁,而且加剧了能源危机.光催化CO_(2)还原不仅可以降低大气中CO_(2)浓度,还可以生产高附加值的燃料和化学品,为CO_(2)循环利用提供了一条有吸引力的途径.在众多半导体材料中,金属卤化物钙钛矿因具有光吸收范围宽、载流子扩散长度长、能级可调等性能而备受关注.特别是以CsPbBr_(3)为代表的铅卤化物钙钛矿在光催化CO_(2)还原中表现出较高活性,具有广阔的应用前景.但是,铅的毒性严重制约了铅基钙钛矿的进一步应用.因此,以铋基卤化物钙钛矿为代表的无铅无毒钙钛矿材料逐渐进入研究者的视野,但铋基钙钛矿材料仍然面临载流子分离效率低和复合严重等问题,还需要深入研究进而提高其光催化活性.石墨烯作为一种高效的电子受体和传输体,可以通过促进光生电子的转移来提高半导体光催化剂的性能.此外,在石墨烯表面锚定单原子可以产生独特的光电效应、更多的反应活性位点以及出色的催化活性和选择性.因此,本文设想引入单原子锚定的石墨烯作为理想的电子介质,通过抑制光生电子和空穴的重组以及促进电荷迁移来提高卤化物钙钛矿光催化CO_(2)还原性能.本文通过原位热解法制备了钴单原子修饰的氮掺杂石墨烯(Co-NG)助催化剂,并进一步通过原位反溶剂结晶法制备了Cs_(3)Bi_(2)Br_(9)/Co-NG复合光催化剂用于光催化还原CO_(2)为CO.通过X射线吸收光谱和高角度环形暗场扫描透射电子显微镜等结果证明了Co-NG助催化剂的成功合成.扫描电镜、透射电镜和X射线光电子能谱等表征结果表明Cs_(3)Bi_(2)Br_(9)/Co-NG复合材料中Cs_(3)Bi_(2)Br_(9)和Co-NG紧密接触并存在明显的电子相互作用.光催化CO_(2)还原测试结果表明,优化后的Cs_(3)Bi_(2)Br_(9)/Co-NG复合材料的CO产率为123.16μmol g^(-1)h^(-1),是纯样Cs_(3)Bi_(2)Br_(9)的17.3倍.此外,Cs_(3)Bi_(

关 键 词：Bismuth-based perovskite Photocatalysis CO_(2) reduction Single-atom cocatalyst Charge separation 

分 类 号：O643.36[理学—物理化学] O644.1[理学—化学]